|Publication number||US7726543 B2|
|Application number||US 12/036,449|
|Publication date||Jun 1, 2010|
|Filing date||Feb 25, 2008|
|Priority date||Sep 14, 2001|
|Also published as||DE10145420A1, DE10145420B4, US7360679, US20040060971, US20080142576, WO2003024653A1|
|Publication number||036449, 12036449, US 7726543 B2, US 7726543B2, US-B2-7726543, US7726543 B2, US7726543B2|
|Original Assignee||Smart Pac Gmbh Technology Services|
|Export Citation||BiBTeX, EndNote, RefMan|
|Patent Citations (16), Classifications (37), Legal Events (1)|
|External Links: USPTO, USPTO Assignment, Espacenet|
This application is a continuation under 37 CFR 1.53(b) of pending prior application Ser. No. 10/416,742 filed on Oct. 29, 2003, now U.S. Pat. No. 7,360,679 and claims the benefit of International Application PCT/DE02/03365 of Sep. 10, 2002, which designated inter alia the United States and which claims the priority of German Application DE 101 45 420.1 of Sep. 14, 2001.
The present invention relates to a method for the production of a soldered joint between at least two contact partners of a bonding arrangement where a formed piece of solder material is arranged at a distance to the bonding arrangement, the formed piece of solder material is at least partially melted off and the at least partially melted off formed piece of solder material is thrust against the bonding arrangement in such a way that both contact partners are wetted to achieve an electrically conductive bond in a bonding area.
U.S. Pat. No. 5,828,031 discloses a method for the production of a soldered joint between two contact partners of a bonding arrangement, with the contact partners being designed as contact surfaces that include a 90° angle. For the production of such a soldered joint, it is described to arrange a formed piece of solder material formed as a solder ball by means of a capillary between the two contact partners in such a way that the result is a contact between the two contact surfaces as well as the capillary. For this purpose, the solder ball is pressed against the contact surfaces by means of the capillary. Such contact must be maintained long enough until a melting of the solder ball by means of laser energy has effected a wetting of the contact surfaces and the resulting adhesive forces, which secure the solder material in the bonding position.
The aforementioned type of generation of the contact pressure between the solder ball and the contact surfaces requires that the capillary for the production of the soldered joint must be positioned directly in the area of the bonding arrangement. For one, this requires an extremely precise positioning of the capillary, and on the other hand, it requires a good accessibility of the bonding arrangement.
The invention is based on the problem of proposing a method for the production of a soldered joint between two contact partners of a bonding arrangement not arranged on the same plane, which requires on the one hand a low positioning effort for the positioning of the capillary, and on the other hand can be executed at a distance to the bonding arrangement, thus requiring lesser requirements with respect to the accessibility of the bonding arrangement.
In the method for the production of a soldered joint in accordance with the invention, a formed piece of solder material is arranged at a distance to the bonding arrangement and thrust or shot against the bonding arrangement following an at least partial melting off of the formed piece of solder material. This thrust motion or ballistic motion of the at least partially melted off formed piece of solder material is such that both contact partners are wetted at the impact or as a result of the impact on the contact partner(s). This can be effected in that both contact partners are impacted simultaneously or one contact partner is impacted first and the wetting of the second contact partner is effected as a result of the ricochet effect. In any case, the wetting of both contact partners results in an electrically conductive joint.
Suitable solder materials are not only conventional materials such as metallic solder alloys, for example, but principally all materials that enable an electrically conductive joint between the contact partners, such as conductive plastic materials, for example.
Compared to the known method, this therefore results in a lesser requirement with respect to the positioning precision of the capillary on the one hand and with respect to the accessibility of the bonding arrangement on the other band, because a mechanical contact chain between the bonding arrangement, the formed piece of solder material and the capillary for the production of the soldered joint is no longer required. Rather, the at least partially melted off formed piece of solder material can be positioned in the area of the bonding arrangement without contact to the capillary. Depending on the geometrical conditions or, for example, even the composition of the solder material, the formed piece of solder material may be thrust and/or shot against the bonding arrangement when only partially melted off or completely melt off. It is essential only that both contact partners are wetted as a result of the impact of the solder material on at least one contact partner of the bonding arrangement.
A particularly advantageous method is thrusting the at least partially melted off formed piece of solder material into a contact gap developed between the contact partners of the bonding arrangement. In such application of the method, it is possible, depending on the development of the gap, to counteract the capillary force acting against the wetting of the entire contact surface of the bonding arrangement with the mass force of the solder material to achieve a dependable soldered joint even with bonding arrangements that are developed rather unfavorably.
Especially with a contact gap that is shaped more or less conically as a result of the bonding arrangement, the application of the method enables a dependable soldered joint if the at least partially melted off formed piece of solder material is thrust into the direction of the bisector of the gap angle developed between the contact partners in the contact gap. The choice of thrust direction according to the bisector of the conical gap is especially advantageous if the contact partners to be wetted are developed as a surface with approximately equally sized contact surfaces.
With a conical development of the contact cap and contact partners being designed as differently sized contact surfaces, it is advantageous if the at least partially melted off formed piece of solder material is thrust into the contact gap along an axis that runs between the bisector of the angle and the larger of the two contact surfaces.
With a bonding arrangement of two contact surfaces arranged in parallel, it is especially advantageous to thrust the at least partially melted off formed piece of solder material into the direction of the center axis of the gap into the parallel gap developed between the contact surfaces of to the bonding arrangement.
In contact surfaces that are arranged relative to one another in this way and/or contact gaps developed in this way, such as is the case, for example, with a so-called flip-chip contacting of a semiconductor component such as a chip, on a substrate, the method thus enables in a first step a defined relative arrangement of the contacting substrates with oppositely arranged connecting surfaces at a precisely adjustable substrate distance and in a second step with precise adherence to the defined substrate distance, a contacting of the substrates by producing a soldered joint by means of a thrust application of the solder material in the contact gap developed between the contact surfaces of the substrates.
With a bonding arrangement comprised of a contact sleeve and a conducting wire running in the contact sleeve, it is advantageous to thrust the at least partially melted off formed piece of solder material into the direction of the run of the conducting wire in the implementation of the method. This application of the method appears especially advantageous when the substrate is assembled with electronic components in SMD technology where the connecting conductors of the components are assembled into the through plating of the substrate and soldered with said through plating.
With a bonding arrangement comprised of a contact surface and a wire conductor arranged on the contact surface, the wire conductor is forced into contact with the contact surface as a result of the thrust of the solder material on the wire conductor. In this way, it is also possible to do without a contact between the contact tool and the wire conductor in a wire conductor connection while establishing the connection.
The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and specific objects attained by its uses, reference is made to the accompanying drawings and descriptive matter in which a preferred embodiment of the invention is illustrated.
In the drawings:
Referring to the drawings in particular,
After the formed piece of solder material 27 has reached the guide channel 26 of the application mouthpiece 25, as shown in
Following the positioning of the formed piece of solder material 27 relative to the bonding arrangement 21 shown in
A temporary or even constant fluid pressure in the guide channel 26 following the at least partial melting off of the formed piece of solder material 27, which is preferably generated by means of a protective gas, effects the ejection of the at least partially melted off formed piece of solder material 27 from the output area 28.
As shown in
As shown in
In the case that the formed piece of solder material 27 impacts the contact surfaces 22, 23 of the bonding arrangement 21 in only partially melted off condition, there is first an at least partial wetting of the contact surfaces 22, 23 corresponding to the portion of the melted off volume of the formed piece of solder material 27. In that case, a complete wetting of the contact surfaces 22, 23 can be ensured in that the formed piece of solder material 27 is repeatedly loaded with energy after the formed piece of solder material 27 has impacted the bonding arrangement 21 until a complete melt off has been achieved.
The application example shown in
To produce soldered joints between the contact surfaces 37, 38 of the individual bonding arrangements 39, the substrate arrangement 47 comprised of the chip 41 and the substrate 42 is defined in its relative positioning as described earlier. Then, as is shown especially in
As already explained in detail above with reference to
To produce a soldered joint 56, shown in
While specific embodiments of the invention have been shown and described in detail to illustrate the application of the principles of the invention, it will be understood that the invention may be embodied otherwise without departing from such principles.
|Cited Patent||Filing date||Publication date||Applicant||Title|
|US5597110 *||Aug 25, 1995||Jan 28, 1997||Motorola, Inc.||Method for forming a solder bump by solder-jetting or the like|
|US5605276 *||Jun 22, 1995||Feb 25, 1997||Nagata; Eishu||Soldering method and soldering apparatus|
|US5868305 *||Sep 22, 1997||Feb 9, 1999||Mpm Corporation||Jet soldering system and method|
|US5878941 *||Jul 25, 1996||Mar 9, 1999||U.S. Philips Corporation||Method of soldering components on a carrier foil|
|US5894980 *||Sep 23, 1996||Apr 20, 1999||Rapid Analysis Development Comapny||Jet soldering system and method|
|US6336581 *||Jun 19, 2000||Jan 8, 2002||International Business Machines Corporation||Solder ball connection device and capillary tube thereof|
|US6543677 *||May 31, 2001||Apr 8, 2003||International Business Machines Corporation||Solder-ball bonding device and method|
|US6589594 *||Aug 31, 2000||Jul 8, 2003||Micron Technology, Inc.||Method for filling a wafer through-via with a conductive material|
|US6595408 *||Oct 7, 1998||Jul 22, 2003||Micron Technology, Inc.||Method of attaching solder balls to BGA package utilizing a tool to pick and dip the solder ball in flux prior to placement|
|US20030226877 *||Jun 5, 2002||Dec 11, 2003||Dean Tran||Thermal solder writing eutectic bonding process and apparatus|
|US20040069758 *||Jun 26, 2002||Apr 15, 2004||Ghassem Azdasht||Method and device for applying a solder to a substrate|
|JP2000228424A||Title not available|
|JP2002064265A||Title not available|
|JPH0623530A||Title not available|
|JPH05226416A||Title not available|
|JPH07202401A||Title not available|
|U.S. Classification||228/179.1, 228/256, 228/260|
|International Classification||H01L21/48, B23K31/02, H05K3/34, B23K3/06, H01L21/60, B23K1/005|
|Cooperative Classification||H01L2924/12042, H05K3/3442, B23K2201/42, H01L2224/81801, H01L2924/014, H05K2203/041, H05K2203/111, H01L2924/01068, H01L2924/01032, H05K2203/0195, B23K3/0623, H01L2924/01033, H01L2924/01005, B23K3/0607, B23K1/0056, H05K3/3436, H01L21/4853, H05K3/3478, H01L24/81, H05K3/3447, H01L2224/75611, H01L2224/811|
|European Classification||H01L24/81, B23K3/06B, B23K1/005R, H05K3/34F6, H01L21/48C4C, B23K3/06B4|